1. Field of the Invention
The present invention relates to control of remote devices, and in particular, control of remotely located electrical equipment, including but not limited to, lighting systems.
2. Problems in the Art
Large area lighting systems are well known in the art. They can take many different forms. From baseball diamonds to playgrounds, to parking lots, to golf courses; large area lighting systems are all around in today""s society.
In some instances, the lighting system is turned on and off automatically by timers, photo detectors, or other devices. This works reasonably well if the lights are used on a regular schedule or according to regularly repeating occurrences. In other cases, employees, staff members, or other persons must be hired or have the obligation to turn on and off the lights, particularly if the lights are used or needed only sporadically. Most of the time the person maintaining the lights will have to take care of several keys for several lights. These people usually travel back and forth between the field and his/her home and even field to field because the lighting is commonly used during non-business hours. In the time it takes a staff member to travel, the lights have been unnecessarily left on. Such a problem is further compounded when the staff member is not informed that the lights are no longer needed for a certain event. When the lights are not turned off, this results in a waste of energy. This waste usually results in a waste of taxpayer""s money. The waste of taxpayer money is furthered by the presence of vandalism, which often occurs to remote lighting systems.
An ancillary problem with manual control of large area lighting systems is that the person in charge normally must handle keys for the electrical boxes or buildings in which the switches or breakers are located to turn the lights on and off. Access by the public at large to the switches is usually blocked for safety, economic, and practical reasons. Such keys must to carefully handles and be available to control the lights. This can be cumbersome.
There has been some work done with computerized control of electrical loads or systems. The computer can have a database of instructions that could include turning a device on or off. The computer could utilize its internal clock or other criteria to issue commands. However, such systems generally require a dedicated computer to control each device or no more than several devices at a location. Such systems also generally require special interactive software developed for each application. To change operation of the computer it must be reprogrammed, or new software must be installed. Either case requires significant time and expense.
Some attempts at remote control have been made. One example uses established paging systems as the carrier of instructions to remotely located devices which are to be controlled. Paging systems are attractive because they have currently developed to a point where they can carry a significant amount of digital data instructions. However, they can be somewhat costly, including communication costs.
The paging system could include a central repository of instructions. Control of remote devices based on the central repository is accomplished by sending out paging messages with control instructions carried therein to a paging receiver at the remote device. While this can eliminate many of the problems associated with other methods of operating lighting systems, a major deficiency with paging systems presently exists. In the United States, paging systems cover most densely populated geographic areas. Most major-sized cities have good coverage. However, coverage is lacking in many other places. Of course, electrical devices, including large area lighting systems, are not limited to big cities. In fact, the need for remote control of devices may be more urgent in less densely populated areas. Thus, while paging systems offer some promise, they simply will not work in some areas because paging communications do not reach those areas.
Furthermore, paging systems tend to be one-way only, and therefore of limited capacity and options. Two-way paging is presently only in development. Digital paging systems are also in development, but it is estimated that infrastructure for substantial geographic coverage is several decades away.
Remote control of devices using DTMF signaling is in use. An example is remote control of the functions of an answering machine by pressing different telephone keys. This can be accomplished over regular or cellular phones. However, because it involves establishing a telephone connection with the remote device, it must use the voice channels. This is not satisfactory. Voice channels are not always available. They can be unreliable. This also involves the cost of using the voice channel while communicating the instructions.
A wireless communications system with more geographical coverage is the cellular telephone system. It is attractive because of this broader geographic coverage and its existent infrastructure. Therefore, like the paging network, capital costs of developing and installing a new infrastructure could be avoided. It is also attractive because it has a built-in confirmation function. However, it is extremely limited in the data that it can carry, especially out to remote devices, without invoking its voice channels. For example, because of inherent limitation in the present cellular communications protocol in the USA (Advanced Mobile Phone Service or AMPS), it may be able to carry only three digits of instructions in each call via the last four digits on each cellular phone""s Mobile Identification Number (MIN), a ten digit number in the form of a conventional telephone number; i.e. abc-def-wxyz, where a,b,c,d,e,f,w,x,y, and z are a single digit including and between 0 and 9, and where abc is the area code (three digits), def is the identification of the local central switching office (CTO) for the land based telephone system (three digits), and wxyz is a four digit identification for the phone (equivalent to the xe2x80x9clinexe2x80x9d number in conventional phone systems). This is well-known and widely documented.
Under Federal Communications Commission (FCC) regulations, two cellular phone carriers for each geographic area are each given 416 duplex voice channels, and 21 control channels. Carrier 1""s channels are called the A channels and carrier 2""s channels are called the B channels. Forward control channels (FOCC""s) are from the cell base station to a cell phone; reverse control channels (RECC""s) are from the phones to the base station. Under AMPS protocol, up to three digits in the MIN can be used for carrying data on the forward control channels.
An advantage of using the control channels of AMPS is that the messages are cheap because they are short and do not involve the voice channels. Also the control channels are transmitted at higher power than the voice channels, have better error correction and better frequency use, and have less traffic. Therefore, they are more reliable as a communication link.
Therefore, current cellular telephone systems and protocols (e.g. Advanced Mobile Phone System (AMPS) in North America; other similar analog systems are NAMPS and ENAMPS) are simply unacceptable because of the limitation of information that could be included as instructions or control in cellular calls.
To have meaningful control of remote devices usually requires communication of more than three digits of instructions. At a minimum, this limitation would not allow an acceptable of level of flexibility for many applications.
Also, the utilization of MINs to both serve to instigate a cellular call and, with the same number, effect an operation (e.g. turning lights on or off) at a remote site is not indicated as a realistic use of MINs or the cellular network.
One example of a cellular telephony based remote control system is that of Cellemetry of Atlanta, Ga. It provides the means of sending short, telemetry-like messages over the cellular telephone system. Examples include reporting (a) alarm panel status, (b) utility meter readings, (c) vehicle and trailer location, and (d) vending machine status. It does utilize the overhead control channels (FOCC""s and RECC""s) of cellular telephone systems to communicate the information. However, its primary uses involve transmitting data or information or status from remote locations to a central location.
One specific example involves soft drink vending machines. Reports can be communicated to a central location regarding how much product has been sold and/or how much money has been received and/or how much change has been dispensed. Another example involves turning off a machine or turning security on at the machine. However, there is no known ability with such systems to have individualized schedules or control options at each remote device that can be handled via the three digits of a cellular control channel registration message sent over the FOCC.
Such a system could use different MINs to set and reset flags in a programmable logic controller (PLC), for example, through a single input/output port, but there is no known controlling of resistive or inductive loads with MINs mapped in a PLC memory to functions. There is no known instruction set coded to MINs. The problem is one of availability of MINs. If each remotely positioned PLC with a cellular radio were given ten instructions to which it would respond, the cellular carrier would have to provide ten unique and distinct MINs for each such radio. If there were only two radios, only 20 MINs would be needed. But one hundred radios would need 1000 MINS. One thousand radios would need ten thousand MINs and so on. If there are any meaningful number of remote devices to be controlled (and remote radios), there would not be enough MINs or the number of MINs per phone would have to be restricted.
Essentially, cellular systems have wider coverage geographically than paging systems, but much more restricted data capacity. Therefore, cellular systems are not indicated to be viable candidates for flexible remote control of devices.
There is no known existing system that remotely controls resistive or inductive electrical loads according to a centralized schedule through the cellular system control channels.
The state of the art has not revealed a way of solving the conflicting concerns of cost, capacity, and coverage relative to centralized, automated control of multiple remotely located electrical devices. Therefore, there is a need for improvement in the art.
A principal object of the present invention is therefore to provide an apparatus and method of controlling remotely located devices, which improves over or solves the problems and deficiencies in the art.
Other objects, features, and advantages of the present invention is to provide an apparatus and method as above described which:
a) Is wireless.
b) Does not require specialized lighting control software or the need for distributed software or updates.
c) Facilitates low cost use of communications networks (e.g. control channel of cellular, Internet).
d) Does not require a dedicated PC at each remote location.
e) Does not require a telephone line for each remote location and eliminates expensive installation of phone lines.
f) Does not require additional phone lines or hard wiring.
g) Reduces human time and the chance of human error.
h) Is cost effective.
i) Reduces staff legwork and time traveling from location to location, before or after events.
j) Eliminates human resources, time, and cost to physically travel to location(s) and manually operate the remote devices.
k) Saves energy by operating the remote devices only when they are needed.
l) Uses existing communications infrastructures (e.g. Internet, telephone networks, cellular networks).
m) Allows for centralized support services.
n) Provides for easy training of end users (operators, customers, and interested persons).
o) Optionally provides a confirmation sent for each new schedule or change.
p) Is especially flexible for variable schedules at multiple locations.
q) Saves time.
r) Saves money.
s) Can be predominately automated.
t) Allows for centralization of data yet distribution of individualized control at each remote device.
u) Reduces need to distribute and track multiple sets of keys.
v) Is vandal resistant.
w) Has significant flexibility.
x) Is retrofittable.
y) Adapts to existing facilities, systems and devices.
z) Is expandable and upgradeable.
aa) Is reliable.
bb) Does not tie up voice channels.
These and other objects, features, and advantages of the present invention will become more apparent with reference to the accompanying specification and claims.
The present invention involves methods and apparatus for controlling remote devices or systems. The present invention details a way for a user to control a plurality of functions at a remote device or location by using the existent cellular telephone system, a control center, and a remote equipment controller at each remote device or system.
A control center is established, preferably including a computer. An end user of a remote device or system can contact the control center, including via Internet, e-mail, phone, cell phone, fax, or even mail, to request performance of operations by the remote device or system according to a schedule. The control center stores the schedule and assigns or codes the desired request to one or more MINs (mobile identification numbers) of a cellular telephone system. The MIN is a ten digit number which correlates to a cellular phone number. The control center is assigned a plurality of MIN""s assigned by a cellular carrier. The MIN""s can be designated with area codes that are not accessible by common carriers. Therefore, a standard cellular phone cannot be called using the MIN""s assigned to the central location.
The remote equipment controller includes a processor with memory that is pre-programmed with the authorized MINs and functions for the particular remote device. The processor is operatively connected to components that can effectuate a function in the remote device upon appropriate instruction from the processor. When the schedule indicates an action should occur at the remote device, the control center retrieves the MIN for the function chosen by the user, and the MIN is sent to the cellular provider. The cellular provider then calls the MIN of the remote radio located on the remote or system. Once the radio receives the call from the cellular provider, it passes all ten digits of the MIN to the processor (e.g. a PLC or programmable logic controller). The processor uses a memory lookup table to map the digits (e.g. the last three digits of the MIN) to a specific pre-programmed function. Once this function is located, the processor then performs this function. Thus, the remotely located device can be controlled, even according to multiple instructions, by communication through the very limited data headroom of the control channel of a cellular telephone system.
Central control can utilize what is called a gateway to the cellular network to communicate to the remote cellular radios and to store both the schedules and the coded MINs.
As used herein, the terms xe2x80x9ccentral controlxe2x80x9d or xe2x80x9ccontrol centralxe2x80x9d refer sometimes to xe2x80x9ccentral controlxe2x80x9d alone and sometimes to xe2x80x9ccentral controlxe2x80x9d and a dedicated gateway to the cellular network. In other words, the functions attributed to central control could be performed with appropriate components completely at central control, or some functions (e.g. storing of database, use of database, interface with the cellular network) could be delegated to another system, such as a gateway system, as will be further discussed below.